1. Field of the Invention
The present invention relates to tools that are used to turn fasteners having lobed drive recesses or sockets. In particular, the invention relates to tools having a generally rounded drive head so as to be tiltable in the fastener drive recess to turn the fastener in a non-coaxial relationship.
2. Description of the Prior Art
The prior art contains a number of tools that have rounded or circular drive heads used to turn fasteners that have polygonal drive sockets or recesses. The purpose of the rounded head is to provide the capability of turning the fastener when the drive tool is disposed in an angular relationship with respect to the fastener's axis. This capability is significant where the fastener is located in a hard to reach place. One such driver is disclosed in U.S. Pat. No. 4,246,811 and is designed for turning a fastener with a polygonal drive recess. The driver has a rounded head which, in longitudinal cross section, is elliptical, resulting in a shape which is rather difficult to fabricate.
Another such driver is disclosed in U.S. Pat. No. 4,824,418, which discloses an articulated joint between two shafts, the one shaft having a lobed recess and the other having an enlarged rounded drive head. Again, however, the drive head in longitudinal cross section defines two non-concentric hemispheres.
One standard type of lobed-recess fastener is that sold by CamCar/Textron under the trademark "TORX" for which there are mateable lobed drivers. Heretofore, however, there have not been provided any effective ball-type TORX drivers to provide non-coaxial driving of a TORX fastener.